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Table Of Contents
Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 64
UG585 (v1.11) September 27, 2016
Chapter 3: Application Processing Unit
3.2 Cortex-A9 Processors
3.2.1 Summary
The APU implements a dual/single-core Cortex-A9 MP configuration. Each processor has its own
SIMD media processing engine (NEON), memory management unit (MMU), and separate 32 KB
level-one (L1) instruction and data caches. Each Cortex-A9 processor provides two 64-bit AXI master
interfaces for independent instruction and data transactions to the SCU. Depending on the address
and attributes, these transactions are routed to the OCM, L2 cache, DDR memory, or, through the PS
interconnect, to other slaves in the PS, or to the PL. Each processor interface with the SCU includes
the required snoop signals to provide coherency between the L1 data caches within the processors
and the shared L2 cache for shareable memory. The Cortex-A9 and its subsystem also provide
complete Trustzone extension, necessary for user security.
The Cortex-A9 processor implements the necessary hardware features for program debug and trace
generation support. The processor also provides hardware counters to gather statistics on the
operation of the processor and memory system.
The major sub-blocks within the Cortex-A9 are the central processing unit (CPU), the L1 instruction
and data caches, the memory management unit (MMU), the NEON coprocessor, and the core
interfaces. Their functions are explained in the following subsections.
3.2.2 Central Processing Unit (CPU)
Each Cortex-A9 CPU can issue two instructions in one cycle and execute them out of order. The CPU
implements dynamic branch prediction and with its variable length pipeline can deliver
2.5 DMIPs/MHz. The Cortex-A9 processor implements the ARMv7-A architecture with full virtual
memory support and can execute 32-bit ARM instructions, 16-bit and 32-bit Thumb instructions,
and 8-bit Java™ byte codes in the Jazelle hardware acceleration state. Figure 3-3 shows the
architecture of the Cortex-A9 processor.